<p>Fields, parameters and return values marked <code>@NotNull</code>, <code>@NonNull</code>, or <code>@Nonnull</code> are assumed to have non-null
values and are not typically null-checked before use. Therefore setting one of these values to <code>null</code>, or failing to set such a class field
in a constructor, could cause <code>NullPointerException</code>s at runtime.</p>
<h2>Noncompliant Code Example</h2>
<pre>
public class MainClass {

  @Nonnull
  private String primary;
  private String secondary;

  public MainClass(String color) {
    if (color != null) {
      secondary = null;
    }
    primary = color;  // Noncompliant; "primary" is Nonnull but could be set to null here
  }

  public MainClass() { // Noncompliant; "primary" Nonnull" but is not initialized
  }

  @Nonnull
  public String indirectMix() {
    String mix = null;
    return mix;  // Noncompliant; return value is Nonnull, but null is returned.}}
  }
</pre>
<h2>See</h2>
<ul>
  <li> <a href="http://cwe.mitre.org/data/definitions/476.html">MITRE CWE-476</a> - NULL Pointer Dereference </li>
  <li> <a href="https://www.securecoding.cert.org/confluence/x/ZwDOAQ">CERT, EXP01-J.</a> - Do not use a null in a case where an object is required
  </li>
</ul>

